diff --git a/.github/workflows/qar_vnext_d3_daily_preview_artifact.yml b/.github/workflows/qar_vnext_d3_daily_preview_artifact.yml
new file mode 100644
index 0000000..d4b86b2
--- /dev/null
+++ b/.github/workflows/qar_vnext_d3_daily_preview_artifact.yml
@@ -0,0 +1,74 @@
+name: QAR vNext D3 Daily Preview Artifact
+
+on:
+  pull_request:
+    paths:
+      - ".github/workflows/qar_vnext_d3_daily_preview_artifact.yml"
+      - "scripts/d3_build_daily_preview_artifact.py"
+      - "scripts/d3_verify_daily_preview_artifact.py"
+      - "src/quant_advisor_research/preview_bundle.py"
+      - "src/quant_advisor_research/advisory_report.py"
+      - "tests/test_d3_daily_preview_artifact.py"
+  workflow_dispatch:
+    inputs:
+      as_of:
+        description: "Representative daily report date"
+        required: true
+        default: "2026-06-20"
+        type: string
+
+permissions:
+  contents: read
+
+jobs:
+  build-and-verify:
+    runs-on: ubuntu-latest
+    timeout-minutes: 15
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v6
+        with:
+          fetch-depth: 0
+      - name: Setup Python
+        uses: actions/setup-python@v6
+        with:
+          python-version: "3.11"
+      - name: Install advisor package
+        run: python -m pip install -e .
+      - name: Build representative daily preview
+        env:
+          AS_OF: ${{ inputs.as_of || '2026-06-20' }}
+          BASE_SHA: ${{ github.event.pull_request.base.sha || github.sha }}
+        run: |
+          set -euo pipefail
+          python scripts/d3_build_daily_preview_artifact.py \
+            --as-of "${AS_OF}" \
+            --political-events examples/political_events.example.csv \
+            --political-watchlist examples/political_watchlist.example.csv \
+            --artifact-dir "${RUNNER_TEMP}/qar-daily-preview" \
+            --evidence-path "${RUNNER_TEMP}/qar-daily-preview-build-evidence.json" \
+            --base-sha "${BASE_SHA}" \
+            --frozen-generated-at "2026-07-15T00:00:00Z" \
+            > "${RUNNER_TEMP}/qar-daily-preview-build-evidence.log"
+          cat "${RUNNER_TEMP}/qar-daily-preview-build-evidence.log"
+      - name: Upload daily preview artifact
+        uses: actions/upload-artifact@v7
+        with:
+          name: qar-daily-preview
+          path: ${{ runner.temp }}/qar-daily-preview
+          if-no-files-found: error
+      - name: Download daily preview artifact
+        uses: actions/download-artifact@v7
+        with:
+          name: qar-daily-preview
+          path: ${{ runner.temp }}/qar-daily-preview-downloaded
+      - name: Read back uploaded artifact
+        env:
+          BASE_SHA: ${{ github.event.pull_request.base.sha || github.sha }}
+        run: |
+          set -euo pipefail
+          python scripts/d3_verify_daily_preview_artifact.py \
+            --artifact-dir "${RUNNER_TEMP}/qar-daily-preview-downloaded" \
+            --evidence-path "${RUNNER_TEMP}/qar-daily-preview-download-evidence.json" \
+            --build-evidence-path "${RUNNER_TEMP}/qar-daily-preview-build-evidence.json" \
+            --base-sha "${BASE_SHA}"
diff --git a/docs/qar_vnext_d3_daily_action_artifact.md b/docs/qar_vnext_d3_daily_action_artifact.md
new file mode 100644
index 0000000..44d902d
--- /dev/null
+++ b/docs/qar_vnext_d3_daily_action_artifact.md
@@ -0,0 +1,12 @@
+# QAR vNext D3 daily action artifact
+
+This workflow is an isolated, repository-representative fixture acceptance slice:
+
+1. Two independent `build_advisory_report(..., cadence="daily")` invocations read the fixed examples CSVs under a harness-only frozen `generated_at` clock. This proves representative-fixture determinism; it is not a live wall-clock guarantee.
+2. Existing `qar.preview_bundle.v1` writes exactly `report.json`, `report.html`, and `manifest.json` under a unique `$RUNNER_TEMP` destination.
+3. The bundle is read back before `actions/upload-artifact@v7`.
+4. The uploaded artifact is downloaded to a separate temporary directory and read back again, bound to the build evidence by full base SHA, source metadata, and all three file hashes.
+
+Both build and download harnesses fail closed unless the exact contract is schema `"5"`, manifest contract `model_recommendations.v5`, cadence `daily`, and bundle contract `qar.preview_bundle.v1`.
+
+Evidence explicitly identifies `source_kind=repository_representative_fixture`; it is not live producer or production-trusted evidence. The workflow does not modify weekly/monthly workflows, publisher, archive/feed, Pages, identity, or persistence. Issue #50 remains the production-trust hardening gate.
diff --git a/scripts/d3_build_daily_preview_artifact.py b/scripts/d3_build_daily_preview_artifact.py
new file mode 100644
index 0000000..32cda63
--- /dev/null
+++ b/scripts/d3_build_daily_preview_artifact.py
@@ -0,0 +1,169 @@
+#!/usr/bin/env python3
+"""Build and locally verify the D3 representative daily preview artifact."""
+from __future__ import annotations
+
+import argparse
+import hashlib
+import json
+import re
+import shutil
+import sys
+import tempfile
+from pathlib import Path
+from unittest.mock import patch
+
+sys.path.insert(0, str(Path(__file__).resolve().parents[1] / "src"))
+
+from quant_advisor_research import advisory_report
+from quant_advisor_research.preview_bundle import PreviewBundleError, build_preview_bundle, read_preview_bundle
+
+
+BASE_SHA_PATTERN = re.compile(r"[0-9a-f]{40}")
+SOURCE_KIND = "repository_representative_fixture"
+SOURCE_SCHEMA_VERSION = "5"
+SOURCE_CONTRACT_VERSION = "model_recommendations.v5"
+BUNDLE_CONTRACT = "qar.preview_bundle.v1"
+CHECKS = [
+    "exact_three_files",
+    "canonical_json_readback",
+    "manifest_hashes",
+    "manifest_source_pair",
+    "relative_html_links",
+    "repeat_build_bytes",
+]
+
+
+def _require_base_sha(value: str) -> str:
+    if BASE_SHA_PATTERN.fullmatch(value) is None:
+        raise PreviewBundleError("base_sha_invalid")
+    return value
+
+
+def _sha256(path: Path) -> str:
+    return hashlib.sha256(path.read_bytes()).hexdigest()
+
+
+def _require_contract(report: dict[str, object], manifest: dict[str, object]) -> None:
+    source = manifest.get("source")
+    if not isinstance(source, dict):
+        raise PreviewBundleError("contract_drift")
+    if report.get("schema_version") != SOURCE_SCHEMA_VERSION or report.get("cadence") != "daily":
+        raise PreviewBundleError("contract_drift")
+    if manifest.get("bundle_contract") != BUNDLE_CONTRACT:
+        raise PreviewBundleError("contract_drift")
+    expected_source = {
+        "schema_version": SOURCE_SCHEMA_VERSION,
+        "contract_version": SOURCE_CONTRACT_VERSION,
+        "cadence": "daily",
+        "as_of": report.get("as_of"),
+        "generated_at": report.get("generated_at"),
+    }
+    if source != expected_source:
+        raise PreviewBundleError("contract_drift")
+
+
+def _evidence(
+    *, output: Path, report: dict[str, object], manifest: dict[str, object], base_sha: str, repeat_equal: bool
+) -> dict[str, object]:
+    return {
+        "source_kind": SOURCE_KIND,
+        "base_sha": base_sha,
+        "bundle_contract": BUNDLE_CONTRACT,
+        "source": {
+            "cadence": report["cadence"],
+            "as_of": report["as_of"],
+            "generated_at": report["generated_at"],
+            "schema_version": report["schema_version"],
+        },
+        "provenance": {
+            "political_events": "examples/political_events.example.csv",
+            "political_watchlist": "examples/political_watchlist.example.csv",
+        },
+        "files": sorted(path.name for path in output.iterdir()),
+        "sha256": {name: _sha256(output / name) for name in ("manifest.json", "report.html", "report.json")},
+        "manifest_source": manifest["source"],
+        "html_links": ["report.json", "manifest.json"],
+        "checks": CHECKS,
+        "repeat_build_bytes": repeat_equal,
+        "deterministic_clock": {"mode": "frozen_harness", "generated_at": report["generated_at"]},
+    }
+
+
+def build(args: argparse.Namespace) -> None:
+    base_sha = _require_base_sha(args.base_sha)
+    output = Path(args.artifact_dir)
+    events = Path(args.political_events)
+    watchlist = Path(args.political_watchlist)
+    if not events.is_file() or not watchlist.is_file():
+        raise PreviewBundleError("fixture_missing")
+    if not args.frozen_generated_at:
+        raise PreviewBundleError("frozen_generated_at_required")
+    repeat_parent = Path(tempfile.mkdtemp(prefix=f".{output.name}.repeat-", dir=output.parent))
+    try:
+        repeat_output = repeat_parent / "preview"
+        with patch.object(advisory_report, "utc_now_iso", return_value=args.frozen_generated_at):
+            first_report = advisory_report.build_advisory_report(
+                as_of=args.as_of,
+                cadence=args.cadence,
+                political_events_path=events,
+                political_watchlist_path=watchlist,
+            )
+            build_preview_bundle(first_report, output)
+            first_evidence = read_preview_bundle(output)
+            second_report = advisory_report.build_advisory_report(
+                as_of=args.as_of,
+                cadence=args.cadence,
+                political_events_path=events,
+                political_watchlist_path=watchlist,
+            )
+            build_preview_bundle(second_report, repeat_output)
+        evidence = first_evidence
+        _require_contract(dict(evidence.report), dict(evidence.manifest))
+        repeat_equal = all(
+            (output / name).read_bytes() == (repeat_output / name).read_bytes()
+            for name in ("manifest.json", "report.html", "report.json")
+        )
+    finally:
+        shutil.rmtree(repeat_parent, ignore_errors=True)
+    if not repeat_equal:
+        raise PreviewBundleError("repeat_build_non_deterministic")
+    payload = _evidence(
+        output=output,
+        report=dict(evidence.report),
+        manifest=dict(evidence.manifest),
+        base_sha=base_sha,
+        repeat_equal=repeat_equal,
+    )
+    evidence_path = Path(args.evidence_path)
+    if evidence_path.exists():
+        raise PreviewBundleError("evidence_exists")
+    evidence_path.write_text(json.dumps(payload, ensure_ascii=False, indent=2) + "\n", encoding="utf-8")
+    print(json.dumps(payload, ensure_ascii=False, sort_keys=True))
+
+
+def parser() -> argparse.ArgumentParser:
+    result = argparse.ArgumentParser()
+    result.add_argument("--as-of", required=True)
+    result.add_argument("--cadence", choices=("daily", "weekly", "monthly"), default="daily")
+    result.add_argument("--political-events", required=True)
+    result.add_argument("--political-watchlist", required=True)
+    result.add_argument("--artifact-dir", required=True)
+    result.add_argument("--evidence-path", required=True)
+    result.add_argument("--base-sha", required=True)
+    result.add_argument("--frozen-generated-at", required=True)
+    return result
+
+
+def main() -> None:
+    try:
+        build(parser().parse_args())
+    except PreviewBundleError as exc:
+        print(f"daily_preview_build_failed:{exc.code}", file=sys.stderr)
+        raise SystemExit(1) from None
+    except (OSError, TypeError, ValueError, UnicodeError):
+        print("daily_preview_build_failed", file=sys.stderr)
+        raise SystemExit(1) from None
+
+
+if __name__ == "__main__":
+    main()
diff --git a/scripts/d3_verify_daily_preview_artifact.py b/scripts/d3_verify_daily_preview_artifact.py
new file mode 100644
index 0000000..bae45a2
--- /dev/null
+++ b/scripts/d3_verify_daily_preview_artifact.py
@@ -0,0 +1,122 @@
+#!/usr/bin/env python3
+"""Read back a downloaded D3 preview artifact without production integration."""
+from __future__ import annotations
+
+import argparse
+import hashlib
+import json
+import re
+import sys
+from pathlib import Path
+
+sys.path.insert(0, str(Path(__file__).resolve().parents[1] / "src"))
+
+from quant_advisor_research.preview_bundle import PreviewBundleError, read_preview_bundle
+
+
+BASE_SHA_PATTERN = re.compile(r"[0-9a-f]{40}")
+SOURCE_KIND = "downloaded_repository_representative_fixture"
+SOURCE_SCHEMA_VERSION = "5"
+SOURCE_CONTRACT_VERSION = "model_recommendations.v5"
+BUNDLE_CONTRACT = "qar.preview_bundle.v1"
+
+
+def verify(args: argparse.Namespace) -> None:
+    if BASE_SHA_PATTERN.fullmatch(args.base_sha) is None:
+        raise PreviewBundleError("base_sha_invalid")
+    output = Path(args.artifact_dir)
+    evidence = read_preview_bundle(output)
+    report = dict(evidence.report)
+    manifest = dict(evidence.manifest)
+    source = manifest.get("source")
+    expected_source = {
+        "schema_version": SOURCE_SCHEMA_VERSION,
+        "contract_version": SOURCE_CONTRACT_VERSION,
+        "cadence": "daily",
+        "as_of": report.get("as_of"),
+        "generated_at": report.get("generated_at"),
+    }
+    if (
+        not isinstance(source, dict)
+        or report.get("schema_version") != SOURCE_SCHEMA_VERSION
+        or report.get("cadence") != "daily"
+        or manifest.get("bundle_contract") != BUNDLE_CONTRACT
+        or source != expected_source
+    ):
+        raise PreviewBundleError("contract_drift")
+    try:
+        build_evidence = json.loads(Path(args.build_evidence_path).read_text(encoding="utf-8"))
+    except (OSError, TypeError, ValueError, UnicodeError):
+        raise PreviewBundleError("build_evidence_invalid") from None
+    if not isinstance(build_evidence, dict):
+        raise PreviewBundleError("build_evidence_invalid")
+    if (
+        build_evidence.get("source_kind") != "repository_representative_fixture"
+        or build_evidence.get("base_sha") != args.base_sha
+        or build_evidence.get("bundle_contract") != BUNDLE_CONTRACT
+        or build_evidence.get("manifest_source") != source
+    ):
+        raise PreviewBundleError("build_evidence_mismatch")
+    expected_hashes = build_evidence.get("sha256")
+    if not isinstance(expected_hashes, dict):
+        raise PreviewBundleError("build_evidence_invalid")
+    actual_hashes = {
+        name: hashlib.sha256((output / name).read_bytes()).hexdigest()
+        for name in ("manifest.json", "report.html", "report.json")
+    }
+    if (
+        expected_hashes != actual_hashes
+        or build_evidence.get("files") != ["manifest.json", "report.html", "report.json"]
+        or build_evidence.get("source") != {
+            "cadence": "daily",
+            "as_of": report.get("as_of"),
+            "generated_at": report.get("generated_at"),
+            "schema_version": SOURCE_SCHEMA_VERSION,
+        }
+    ):
+        raise PreviewBundleError("build_evidence_mismatch")
+    payload = {
+        "source_kind": SOURCE_KIND,
+        "base_sha": args.base_sha,
+        "bundle_contract": BUNDLE_CONTRACT,
+        "source": source,
+        "files": sorted(path.name for path in output.iterdir()),
+        "sha256": {
+            name: hashlib.sha256((output / name).read_bytes()).hexdigest()
+            for name in ("manifest.json", "report.html", "report.json")
+        },
+        "checks": [
+            "exact_three_files",
+            "canonical_json_readback",
+            "manifest_hashes",
+            "manifest_source_pair",
+            "relative_html_links",
+        ],
+        "build_evidence_bound": True,
+    }
+    evidence_path = Path(args.evidence_path)
+    if evidence_path.exists():
+        raise PreviewBundleError("evidence_exists")
+    evidence_path.write_text(json.dumps(payload, ensure_ascii=False, indent=2) + "\n", encoding="utf-8")
+    print(json.dumps(payload, ensure_ascii=False, sort_keys=True))
+
+
+def parser() -> argparse.ArgumentParser:
+    result = argparse.ArgumentParser()
+    result.add_argument("--artifact-dir", required=True)
+    result.add_argument("--evidence-path", required=True)
+    result.add_argument("--build-evidence-path", required=True)
+    result.add_argument("--base-sha", required=True)
+    return result
+
+
+def main() -> None:
+    try:
+        verify(parser().parse_args())
+    except (PreviewBundleError, OSError, TypeError, ValueError, UnicodeError):
+        print("daily_preview_readback_failed", file=sys.stderr)
+        raise SystemExit(1) from None
+
+
+if __name__ == "__main__":
+    main()
diff --git a/tests/test_d3_daily_preview_artifact.py b/tests/test_d3_daily_preview_artifact.py
new file mode 100644
index 0000000..9f8d935
--- /dev/null
+++ b/tests/test_d3_daily_preview_artifact.py
@@ -0,0 +1,141 @@
+from __future__ import annotations
+
+import json
+import subprocess
+import sys
+from pathlib import Path
+
+
+ROOT = Path(__file__).resolve().parents[1]
+BUILD = ROOT / "scripts/d3_build_daily_preview_artifact.py"
+VERIFY = ROOT / "scripts/d3_verify_daily_preview_artifact.py"
+BASE_SHA = "c5ba801a8696eec63c7ba348f3f125cb52cd06ff"
+
+
+def run_script(script: Path, *args: str) -> subprocess.CompletedProcess[str]:
+    return subprocess.run(
+        [sys.executable, str(script), *args],
+        cwd=ROOT,
+        text=True,
+        capture_output=True,
+        check=False,
+    )
+
+
+def build_args(output: Path, evidence: Path) -> tuple[str, ...]:
+    return (
+        "--as-of",
+        "2026-06-20",
+        "--political-events",
+        str(ROOT / "examples/political_events.example.csv"),
+        "--political-watchlist",
+        str(ROOT / "examples/political_watchlist.example.csv"),
+        "--artifact-dir",
+        str(output),
+        "--evidence-path",
+        str(evidence),
+        "--base-sha",
+        BASE_SHA,
+        "--frozen-generated-at",
+        "2026-07-15T00:00:00Z",
+    )
+
+
+def test_representative_daily_build_emits_deterministic_evidence(tmp_path):
+    output = tmp_path / "preview"
+    evidence = tmp_path / "evidence.json"
+    result = run_script(BUILD, *build_args(output, evidence))
+
+    assert result.returncode == 0, result.stderr
+    assert {item.name for item in output.iterdir()} == {"report.json", "report.html", "manifest.json"}
+    payload = json.loads(evidence.read_text(encoding="utf-8"))
+    assert payload["source_kind"] == "repository_representative_fixture"
+    assert payload["base_sha"] == BASE_SHA
+    assert payload["bundle_contract"] == "qar.preview_bundle.v1"
+    assert payload["source"] == {
+        "cadence": "daily",
+        "as_of": "2026-06-20",
+        "generated_at": "2026-07-15T00:00:00Z",
+        "schema_version": "5",
+    }
+    assert payload["checks"] == [
+        "exact_three_files",
+        "canonical_json_readback",
+        "manifest_hashes",
+        "manifest_source_pair",
+        "relative_html_links",
+        "repeat_build_bytes",
+    ]
+    assert payload["repeat_build_bytes"] is True
+
+
+def test_verify_rejects_tampered_artifact(tmp_path):
+    output = tmp_path / "preview"
+    evidence = tmp_path / "evidence.json"
+    assert run_script(BUILD, *build_args(output, evidence)).returncode == 0
+    (output / "report.html").write_text("tampered", encoding="utf-8")
+
+    result = run_script(
+        VERIFY,
+        "--artifact-dir",
+        str(output),
+        "--evidence-path",
+        str(tmp_path / "downloaded-evidence.json"),
+        "--build-evidence-path",
+        str(evidence),
+        "--base-sha",
+        BASE_SHA,
+    )
+
+    assert result.returncode != 0
+    assert "readback_failed" in result.stderr
+
+
+def test_build_rejects_non_daily_source_before_output(tmp_path):
+    result = run_script(
+        BUILD,
+        "--as-of",
+        "2026-06-20",
+        "--cadence",
+        "weekly",
+        "--political-events",
+        str(ROOT / "examples/political_events.example.csv"),
+        "--political-watchlist",
+        str(ROOT / "examples/political_watchlist.example.csv"),
+        "--artifact-dir",
+        str(tmp_path / "preview"),
+        "--evidence-path",
+        str(tmp_path / "evidence.json"),
+        "--base-sha",
+        BASE_SHA,
+        "--frozen-generated-at",
+        "2026-07-15T00:00:00Z",
+    )
+
+    assert result.returncode != 0
+    assert not (tmp_path / "preview").exists()
+    assert "daily_only" in result.stderr
+
+
+def test_verify_rejects_build_evidence_base_mismatch(tmp_path):
+    output = tmp_path / "preview"
+    evidence = tmp_path / "evidence.json"
+    assert run_script(BUILD, *build_args(output, evidence)).returncode == 0
+    payload = json.loads(evidence.read_text(encoding="utf-8"))
+    payload["base_sha"] = "0" * 40
+    evidence.write_text(json.dumps(payload), encoding="utf-8")
+
+    result = run_script(
+        VERIFY,
+        "--artifact-dir",
+        str(output),
+        "--evidence-path",
+        str(tmp_path / "downloaded-evidence.json"),
+        "--build-evidence-path",
+        str(evidence),
+        "--base-sha",
+        BASE_SHA,
+    )
+
+    assert result.returncode != 0
+    assert "readback_failed" in result.stderr